This paper offers a review of the argumentation-theoretical literature on metaphor in argumentative discourse. Two methodologies are combined: the pragma-dialectical theory is used to study the argumentative functions attributed to metaphor, and distinctions made in metaphor theory and the three-dimensional model of metaphor are used to compare the conceptions of metaphor taken as starting point in the reviewed literature. An overview is provided of all types of metaphors distinguished and their possible argumentative functions. The study reveals that not all possible argumentative functions of metaphor have been taken into account, such as the role of conventional direct metaphors in standpoint and starting point. Novel direct metaphor as ...